Differential power-transmission device



Feb. 12; 1929.

2 Sheets-Sheet l V mes kiyw/z-s' Feb. 12, 1929. 7 1,701,723

J. W. LYONS DIFFERENTIAL POWER-TRANSMISSION DEVICE 2 SheetsSheet 2 Patented Feb. 12, 1929. i 1,701,723:

UNITED STATES PATENT OFFICE. i I i I JAMES W. LYONS, or A1; PARK, ILmivoIs, it

DIFFERENTIAL rowzaa-trannsmission nnvron. Application filed 2, 1328. Serial 74 564.

This invention relates to differential power shafts or members 1 and 2 will be designated transmission devices. i the first and second rotatable members,

- Objects of theinvention are: respectively. p i To provide a device for the purpose speci- "l Vhat I now consider the preferable emlied in which all moving parts will have bodimen't of my invention comprises a plu 60 rolling contacts only, thus practically elirnirality of, as shownfour, transn'iission shafts 3, nating friction loss so that it may operate 3, S and 3 mounted in symmetrical spaced with a minimum of lubrication; which, relation to the rotatable members 1 and 2, through the multiplication of transmission so as to be freely movable about said r0taelements, provides for the transmission of table members and also on theirown' axes, 65

power by means of a mechanism of relasecured to opposite ends of which are what, tively very small size, thus rendering it for purposes of convenient reference, will adaptable for a wide range of application be designated traction heads, comprising sets and use; which is very strong and, dueto the of heads a, 4;, 4 and 4 and 5, 5, 5 and fact that sliding contacts are practically 5 which, respectively, in operation, are 70 eliminated, very durable; to provide a'dcvice adapted to run in contact with internal cirwhich is very simple as regards its physical cular treads 6 and 7 formed in the bearing structure and, consequently, inexpensive to support a. and in flange 8 on ahead 9 manufacture; and which develops relatively secured to the" second rotatable member 2,

great efficiency in operation, as compared rotatably mounted in the bearing support 7 with all devices for the transmission of a preferably bymeans of an-anti-friction power of which I have any knowledge. bearing designated as a whole B. Saidbear- To effect the objectsof the invention, my ingfmay exemplify any desired or approved improved power transmission device comformof anti-friction bearing,theparticular prises the various features, combinations of bearing shown forming the subject-matter features and details of construction hereinof an application for U. S. Letters Patent,

after described and claimed. heretofore filed by me in the Patent Office In the accompanying. drawings, in which on or about the 28rd day of April, 1928,and my invention is fully illustrated: numbered serially 272,138, to whlch reference Figure 1 isa sectional elevation of a power is here made for a description thereof in transmission device embodying my lnvention detail.

and improvements, the section being sub- As shown, the traction heads 4 to 4 and stantially on the line 1-1 of Fig. 2; p 5 to 5 have plain cylindrical surfaces, but

s Figure 2'is anend elevation from the left my, invention contemplates the use of other side of Fig. 1; forms of tractionheads, if desired? Figure 3 is a sectional elevation on the The transmission shafts3to 8 have operaline 33 of Fig. 1 and tive connection with the first rotatable Figure 4 is a sectional elevation on the member 1, constructed and arranged to line iti of Fig. 1. impart planetary movement thereto about the 40 Describingthe invention with reference rotatable members 1 and-2 in the same to the drawings, A designates the frame of direction as the first rotatable member 1, the device as a whole, comprising a base while, at the same time, permitting said portion an adapted to be bolted or otherwise shafts to move outwardly away from said secured to a suitable foundationor support, rotatable members under centrifugal force formed on which are spaced bearing supdue to rotation at high speed of said first 10 ports a, a. i rotatable member, thereby effecting pressure As shown, my improved power transmiscontact'of said traction heads 4 to 4 and 5 sion device is designed and adapted for im-i too respectively, with the threads 6 and 7 parting rotation from a shaft 1, whiclimay on the bearing support a and flange 8 of the exemplify'the shaft of an-electricmotor or head 9, respectively, corresponding to the other rotatable power driven member, toa rate of rotation of the first rotatable main? shaft 2, which may exemplify any rotating her, contact of the traction heads 4 to 4' with part, at a differential rate of speed orR. the fixed tread 6 on the bearing support a P. M i operating, in an ohvious'manner to impart For purposes of convenient reference, the independent axial, rotation to said traction heads and thus to the transmission shafts 3 to 3 and with them to the traction heads 5 to 5 all in a direction opposite to that of the first rotatable member. Obviously, also, contact of the traction heads 5 to 5 if ofsmaller diameter than the diameter of the heads l to a, with the tread 7 while'rotating ment to the second rotatable member at av rate of speed or P. M., different from that of the first member, either in the same or opposite direction from said first member, as the traction heads 5 to 5 are smaller or larger than the heads 4 to P, relatively small traction heads 5 to 5 imparting rotation to said second rotatable member in,

the same direction as the first rotatable member, and relatively large traction heads 5 to 5 imparting rotation to said second rotatable member in a direction opposite to the first rotatable member.

The diameter of the fixed tread .6 and the relative diameters of the traction heads 4 to i and 5 to 5 are the controlling factors in the direction and rate of rotation or R. R M. of the second rotatable member relative to the first rotatablemember.

Specifically and preferably, the manner of mounting the transmission shafts 3 to 3 is as follows: Secured to the first rotatable member 1 is what may be designated a spider 10 provided with peripheral cradles or recessed seats 11, and adjusted over the transmission shafts 3 to 3 between the traction heads 4: to P and 5 to 5 respectively, secured to opposite ends thereof, are anti-friction bearing members, indicated at 12, and which may exemplify any formof anti-friction bearing suitable for the purpose, a desirable and preferable form of anti-friction bearing being that which forms the subjectmatter of my said application for U. S. Letters Patent Serial Number 272,138.

The shells or casings of said anti-friction bearings are fitted tothe cradles or recessed seats 11 on the spider 10 with slight clearance, and said bearing member and with them the transmission shafts 3 to 3 are pro: pellcd around the rotatable members 1 and 2 by rigid parts 13 of the spider 10 which form the cradles or seats 11, and which extend between adjacent bearing numbers 12,

the relation being such that the initial action of the spider as rotation of the first rotatable member begins, will be in the nature of awedging action which will force the bearing members 12 and transmission shafts 3 to 3 outwardly'to effect pressure contact of the traction heads 4: to P and 5 to 5 with theirrespective treads 6 and 7, the pressure of said traction heads against their treads being increased by centrifugal force as the speed of said first rotatable member increases. i

A great advantage inherent in my improved transmission device, is that, due to the use of a plurality of transmission shafts, the total power transmitted by the device will bedistributed equally among the different shafts, thus pro vidingby increasing the number of transmission shaftsfor transmitting great power by means of a relatively very small device, the individual parts of which will transmit only a small fraction of the total load, thereby rendering it possible to make individual parts of the device rela5 tively very light and correspondingly reducing the cost of production.

A feature inherent in my improved power transmission device to which I deem it desirable to call particularattention that the traction heads 4: to a and 5 to F acting on respective concentric treads 6 and 7 under the great ,centrifugalforce which they, together with the transmission shafts 3 to 3 and the anti-friction bearingmembers 12 a will develop in operation, will effect and maintain parallelism of said transmission shafts with the rotatable members 1 and 2, thusv rendering negligible any tendency of the traction heads 5 to 5 to drag under the resistance of the load to which the second rotatable member will besubjected in use.

Particular advantages of my improved power transmission device, are: r

1. The great power which may be transmitted by a relatively very small device,

2. The relatively light duty to which the separate parts of the device willbe sub jected in operation,

3. The consequent very small size and compactness of the device,

4. Its simplicity,

5. Its low cost of manufacture and main tenance,

6. The elimination of friction in the device by providing rolling contacts only, and

7. The elimination of all means other than centrifugal force for producing operating pressure contacts in power transmission devices of the type commonly known as friction transmissions.

I claim: a

1. In a differential power transmission device, the combination of rotatable members mounted in axial alignment with each other, comprising a first member adapted to be power driven, and a second member, transmission shafts mounted in spaced relation to said rotatable members so as to be bodily rotatable about the same in a circular orbit anr also rotatable on their own axes, means rendered operative by rotation of said first rotatable member for imparting planetary rotation to said transmission shafts about said rotatal'ile members con;

structed and arranged to permit movement thereof outwardly relative to said rotatable members under centrifugal force, traction heads secured to said transmission shafts and arranged in sets, parts provided with interior treadsopposed to dilferent sets of traction heads on said transmission shafts, comprising; a fixed part and a part rotatable with said second rotatable member, the traction heads of the same set being of the same diameter and of different sets being of different diameters and the diameter of the tread for the larger set of traction heads being equal to that of the tread for the smaller set plus the difference in the diameters of the traction heads of different sets, centrifugal force operating to effect and maintain engagement of the trace tion heads of different sets with the treads opposed thereto, respectively, and also form ing the sole means for effecting and maintaining parallelism of the transmission shafts with said rotatable member and with each other in operation.

2. A differential power transmission device as specified in claim 1,in which the means for mounting said transmission shafts and for imparting planetary rotation there to, comprises bearing members to which, respectively,-a transmission shaft is fitted so as to turn freely, and a spider secured to said first rotatable member provided with seats in which the bearing members for said transmission shafts are loosely confined.

3. A differential power transmission device as specified in claim 1, in which the traction heads of different sets are spaced apart, and the means for mounting said transmission shafts and for imparting planetary rotation thereto, comprises hearing members to which, respectively, a transmission shaft is fitted so as to turn freely, said bearing members comprising a bearing member on each transmission shaft positioned between the traction heads thereon, and a spider secured to said first rotatable member provided with seats in which the bearing members for said transmission shafts are loosely confined. 7

4.- A differential power transmission device as specified in claim 1, in which the "traction heads of dilferentsets are spaced apart, and the means for mounting said transmission shafts and for imparting planetary rotation thereto, comprises bearing members to which, respectively, a transmission shaft is fitted so as to turn freely, said bearing meml'iers comprising a single bearing member on each transmission shaft positioned between the traction heads thereon, and a spider secured to said first rotatable member provided with seats in which the bearing members for said transmission shafts are loosely confined.

5. A differential power transmission'device as specified in claim 1, in which the means for mounting said transmission shafts and for imparting planetary rotation thereto, comprises anti-friction bearing members to each of which, respectively, a transmis sion shaft is fitted so as to turn freely, said bearing members, respectively, comprisinga casing which encloses the anti-friction members thereof, and a spider secured to said first rotatable member provided with seats in which the casings of said bearing members are loosely confined.

6. A differential power transmission device as specified in claim 1, in which the means for mounting said transmission shafts and for imparting planetary rotation thereto about said rotatable members comprises a bearing member on each of said shafts and a spider secured to the first rotatable member provided with seats in which, respectively, bearing members on different transmission shafts are confined, the initial ac tion of said spider on said bearing members being a wedging action, whereby, as rotation of the first rotatable member begins, said bearing members and with them the transmission shafts will be forced outwardly to effect engagement of the sets of traction heads on said transmission shafts with the treads opposed tiereto, respectively.

In witness that I claim the foregoing as my invention, I affix my signature this 28th day of April, A. D. 1928.

JAMES W. LYONS. 

